Removing live-premount modules script, not needed anymore.

This script did two things:

  * forcefully load ide-generic to workaround a bug in qemu bios
    that made it hang during ide detection. This has been fixed
    4 years ago in qemu, so it's not required to do this anymore.

  * forcefully load esp on sparc. This is being loaded automatically
    by udev these days and should be reliable enough.